The figure consolidated wind power as the third main contributor to Spain’s electricity system last year, ahead of coal fired generation, which covered 12.7% of demand after generating 27% less power than the year before.
Combined-cycle gas and nuclear generation remained the biggest contributors, covering 30.4% and 20% of demand respectively. In absolute terms, wind produced 36,188 GWh of power over 2009, up 15.6% from 2008.
Second generator November-December Despite the annual production lead over wind by Spain’s 7.7GW nuclear capacity, winter weather pushed monthly wind production ahead into second place in December, for the second month running, covering 20.1% of demand, compared to nuclear’s 17.4% (table). Gas came top, covering 28,4%.
Already in November, wind had covered 21.2% of demand against nuclear’s 19.5%. Wind’s contribution meant that Spanish renewables covered 34% of total monthly demand in December and accounted for 26% of the Spanish system’s total annual electricity generation over 2009.
Cut at its peak In the small hours of December 30, wind penetration hit a momentary record, covering 54.1% of national demand, beating the previous record of 53.7%, reached on November 8.
Nevertheless, torrential rain produced by the same weather system also forced REE to curtail 600MW of wind power, preventing December’s spot penetration record from going even higher.
REE explains the rain forced hydroelectric reservoirs to unload excess water. High wind production had already pushed conventional thermal power to a technical minimum.
At that point, generators are at minimum turnover but can be quickly cranked up again to meet any unexpected surge in demand or unexpected dropout of generation capacity elsewhere.
Down beyond the minimum, generators must be shut down, and cannot be used for emergency rapid response. In order not to lose its rapid-response safety net, REE pulled the plug on the 600MW of wind.
"Above wind’s must-run status is the electricity system’s security," says Sergio de Otto, communications director at Spanish wind association, Asociación Empresarial Eólica (AEE).
"As with the previous few cases of curtailed wind generation, we’re talking about short-lived, exceptional circumstances, representing a drop in the ocean against annual wind performance," points out AEE president José Donoso.
"That’s not to say we do not make finding ways to avoid curtailment a priority, he adds, but it puts the small anomalies in the context of the wind sector’s huge achievement of becoming a mainstream generation technology and highlights our tremendous and pioneering efforts at integrating wind power within the electricity system."
Integrating increasing amounts of wind is an ongoing affair, says Donoso "but if REE told us a decade ago we could not go beyond 12% spot penetration, look at us now, with over 54%."